CN110588502A

CN110588502A - Automobile brake lamp signal acquisition method and system

Info

Publication number: CN110588502A
Application number: CN201910915052.4A
Authority: CN
Inventors: 吕凌志; 李海霞; 何晨雨
Original assignee: Chongqing Changan Automobile Co Ltd
Current assignee: Chongqing Changan Automobile Co Ltd
Priority date: 2019-09-26
Filing date: 2019-09-26
Publication date: 2019-12-20

Abstract

The invention provides a method and a system for collecting brake lamp signals, wherein the method comprises the steps that an ESC module of a vehicle stability control system is used for obtaining hydraulic signals of a brake system, then an ECU of the ESC is used for calculating hydraulic pressure of a brake pipeline, when the hydraulic pressure value is higher than a threshold value, the brake lamp signals are output to a CAN bus of a whole vehicle to form brake CAN signals, and other controllers receive the brake CAN signals from the CAN bus according to requirements for judging functions of the controllers. The brake lamp signal of the invention is sent out by ESC module through hydraulic signal simulation, no longer use the sole, specialized brake lamp switch, but ESC module is the existing module of the whole car, it is not specialized, on the premise of achieving the equivalent function like this, the invention can not rely on the brake lamp switch to work, can lower costs, reduce and arrange the difficult point.

Description

Automobile brake lamp signal acquisition method and system

Technical Field

The invention relates to a signal acquisition technology, in particular to an automobile brake lamp signal acquisition technology.

Background

The brake lamp signal is one of important signals of an automobile brake system, the brake lamp signal is transmitted on a whole automobile CAN bus, and each controller with requirements on the automobile CAN acquire the signal from the CAN bus for logic judgment.

At present, a brake lamp signal of an automobile is sent out through a brake lamp switch, the brake lamp switch is usually installed on a brake pedal support and is connected with a wiring harness of the whole automobile in an inserting mode, and the structure is shown in a figure 1. The working principle is as follows: the driver steps on the brake pedal, pedal arm 3 drives brake lamp switch contact 31 to rotate around pivot 2 on support 1 and move down, ejector pin 41 extension (extension length is greater than switch switching signal position) of brake lamp switch 4, and then switch break-make voltage state, voltage signal passes through plug connector 5, certain controller 7 (this controller CAN be but not limited to engine controller EMS) of whole car is transmitted to on pencil 6, controller 7 handles after receiving the signal, turn into the CAN signal that CAN transmit on whole car network CAN bus 8, this CAN signal is gathered according to the demand to other controllers of vehicle, be used for vehicle control.

Based on the above, the current method for acquiring the brake light signal needs to be realized through a special brake light switch. On one hand, the cost is higher in consideration of the need of a brake lamp switch, a related wire harness, a plug connector and the like; on the other hand, the brake lamp switch is arranged on the brake pedal and is limited by space, and meanwhile, the switching time needs to be considered, so that the design difficulty is increased; in addition, the stop lamp switch is used as an assembly, so that the process cost is increased.

Disclosure of Invention

The invention aims to provide a method and a system for acquiring a brake lamp signal, which can work independently of a brake lamp switch so as to reduce the cost, the difficulty in arrangement and the assembly cost.

The technical scheme of the invention is as follows:

the invention relates to a brake lamp signal acquisition method, which simulates a brake lamp switch signal by utilizing a hydraulic signal of an ESC module of a vehicle stability control system and comprises the following steps: the ESC module of the vehicle stability control system acquires a hydraulic signal of a brake system, an ECU of the ESC module calculates the hydraulic pressure of a brake pipeline, when the hydraulic pressure value is higher than a threshold value, a brake lamp signal is output to a CAN bus of the whole vehicle to form a brake CAN signal, and other controllers collect the brake CAN signal from a CAN network according to requirements for self function judgment.

Based on the method, the invention further provides a brake lamp signal acquisition system, which comprises a pedal bracket, a rotating shaft, a pedal arm, a booster push rod, a main cylinder, a brake oil pipe, an ESC module and a CAN bus; the ESC module is internally provided with a liquid sensor, an internal wire harness and a controller ECU;

when a driver treads a brake pedal, a pedal arm rotates around a rotating shaft on a pedal support to push a booster push rod to move, and the booster push rod pushes a piston of a main cylinder to move forwards to establish hydraulic pressure; high-pressure brake fluid enters the ESC module through a brake oil pipe, a hydraulic sensor in the ESC module detects the brake fluid pressure, and the ESC module simulates brake lamp signals through a logic algorithm and outputs the brake lamp signals to a CAN bus of the whole vehicle.

The invention has the advantages that: the stop lamp signal is sent out by the ESC module through hydraulic signal simulation, and a separate and special stop lamp switch is not used. The ESC module is an existing module of the whole vehicle and is not special, so that system hardware can be simplified and purchasing, designing and assembling costs can be reduced on the premise of realizing the same function.

Drawings

FIG. 1 is a schematic diagram of background art;

FIG. 2 is a diagram of the hardware architecture of the present invention;

FIG. 3 is a logic flow diagram of the present invention.

In the figure, 1-bracket, 2-rotating shaft, 3-pedal arm, 31-switch contact, 4-brake lamp switch, 41-ejector rod, 5-plug connector, 6-wire harness, 7-controller, 8-CAN bus, 9-booster push rod, 10-master cylinder, 11-brake oil pipe, 12-ESC module, 121-hydraulic sensor, 122-internal wire harness and 123-controller ECU.

Detailed Description

The invention is further described with reference to the accompanying drawings in which:

referring to fig. 2, the hardware architecture of the present invention is as follows:

for the system, the brake lamp signal acquisition method is realized by using the existing hardware of the whole vehicle. The whole system mainly comprises a pedal bracket 1, a rotating shaft 2, a pedal arm 3, a booster push rod 9, a master cylinder 10, a brake oil pipe 11, an ESC module 12, a CAN bus 8 and other components, and the connection structure and the arrangement mode of the components are basically the same as those of the prior art. The ESC module is internally provided with a liquid sensor 121, an internal wiring harness 122 and a controller ECU123, and the core is that the ESC123 simulates a brake lamp signal through a logic algorithm.

For the brake pedal, a brake lamp switch assembly in the traditional scheme is eliminated, and a mounting structure, a plug connector, a wiring harness lamp and the like associated with the brake lamp switch assembly are synchronously eliminated, so that system hardware is simplified, and purchasing, design and assembly costs are reduced.

Referring to FIG. 3, the logic flow of the present invention is described as follows:

when a driver steps on a brake pedal, the pedal arm 3 rotates around the rotating shaft 2 on the bracket 1 to push the push rod 9 of the booster to move.

The booster push rod 9 pushes the piston of the master cylinder 10 forward, building up hydraulic pressure, specifically the pressure increases starting from 0 Mpa.

High-pressure brake fluid enters the ESC module 12 through the brake oil pipe 11, a hydraulic pressure sensor 121 in the ESC module 12 detects the brake fluid pressure and converts the brake fluid pressure into an electric signal, the electric signal is transmitted to the controller ECU123 through the internal wiring harness 122, and the controller ECU123 converts the received electric signal into a pressure value. The above functions are the existing functions of the ESC module at present, and the algorithm of the ESC module has different difference according to different hardware, but can convert digital pressure information.

The invention adds a brake lamp signal simulation algorithm in the existing ESC module 12, and sends out an appointed CAN signal to the CAN bus 8 according to the CAN signal coding rule when the brake fluid pressure P is detected to be larger than a threshold value. The above threshold is set by the manufacturer according to the actual situation, such as 0.2MPa, and specifically, it is required to be greater than the fluctuation of the braking pressure when the brake is not applied, and it is usually set between 0.1MPa and 0.3 MPa.

The CAN signal is propagated on the CAN bus 8, and each controller with a demand receives the signal for logic judgment of the own function.

The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A method for collecting brake lamp signals is characterized in that a hydraulic signal of a brake system is obtained by an ESC module of a vehicle stability control system, then an ECU of the ESC calculates the hydraulic pressure of a brake pipeline, when the hydraulic pressure value is higher than a threshold value, the brake lamp signals are output to a CAN bus of a whole vehicle to form brake CAN signals, and other controllers collect the brake CAN signals from the CAN bus according to requirements for judging the functions of the controllers.

2. The brake light signal collection method of claim 1, wherein the threshold value is larger than the fluctuation of the brake pressure without braking, and is usually set between 0.1Mpa and 0.3 Mpa.

3. The system for realizing the signal acquisition method of the brake lamp of claim 1 or 2, wherein the system comprises a pedal bracket, a rotating shaft, a pedal arm, a booster push rod, a main cylinder, a brake oil pipe, an ESC module and a CAN bus; the ESC module is internally provided with a liquid sensor, an internal wire harness and a controller ECU;